Earlier this year LG sued Samsung claiming that the firm had infringed a number of its OLED patents in popular devices such as the Galaxy S smartphone and Galaxy Tab. In total LG claimed five of Samsung's products infringed its patents, a claim that Samsung denies.

Samsung has now filed a patent invalidation lawsuit against LG in a South Korea intellectual property tribunal. The firm claims that seven patents pertaining to OLED technology held by LG are invalid because they lack innovation.

Samsung and LG have been bitter rivals long before smartphones became a fashionable accessory. Both firms are also big players in the display market and while OLED technology is common in smartphones it is expected to start appearing in larger sizes in the coming years.

Should LG's patents be invalidated it will be a hard blow for LG, which has invested heavily in OLED development in the past five years. µ